Bending object gives it a tilt
It looks like your object is a bit tilted. You can simply correct the Axis value it in the Operator box:

Or you can create a new Transform Orientation (&quot;+&quot; button), to keep it selected in the panel:

Then spin the face:

But as you see it makes the shape go down on the Z axis, is it what you want? If not, you could use the CtrlE &gt; Bridge Edge Loops instead. Duplicate the face, align it with the global axis:

Use the Bridge Edge Loops tool, tweak the parameters in the Operator box:


For the second shape you show, I would do it this way:

Create an angle:



Move up the tip:



Bevel the angle:



Extrude along normals, etc...